From Magellanic Clouds to the Magna Carta
A New Imaging System Leads to Groundbreaking Discoveries
Members of the Harvard Plate Stacks, R. B. Toth, and Weissman Preservation Center, gather around the Harvard Law Library's copy of the Magna Carta to create multispectral images of this historic document—image courtesy of Samantha M. Joyce.
Normal visible light image of a section of Harvard's Magna Carta, with water damage, and faint text.
Multispectral imaging detail of the same area of the Magna Carta. This monochromatic image was processed to heighten the readability of the ink script. MSI imaging can produce color or black-and-white images, depending on the need.
You may have heard the remarkable news: a copy of the Magna Carta purchased by the Harvard Law Library in 1946 for just $27.50 believed to be a later reproduction, is now confirmed to be one of only seven surviving originals of King Edward I’s 1300 Magna Carta. Surprisingly, a new imaging system being developed at the Harvard Plate Stacks at the Center for Astrophysics | Harvard & Smithsonian played a crucial role in this historic revelation.
On March 19, 2024, the Harvard Plate Stacks, in collaboration with R.B. Toth Associates LLC and the Weissman Preservation Center, tested a new glass plate imaging system prototype. The demonstration involved capturing multispectral images of four items from various Harvard libraries, aiming to showcase the system, gather expert feedback, and spark cross-disciplinary collaboration. Among the test subjects was a dull tan piece of parchment covered in Latin script. The wording is smudged, faint, and illegible in different areas and degrees across the rectangular piece of velum. At the time, this was thought to be a 1327 copy of the 1300 version of the Magna Carta signed by Edward I of England.
Using an achromatic Phase One camera and a sophisticated lighting rig designed by R.B. Toth, the team illuminated the parchment in 15 narrow bands of light—from two ultraviolet wavelengths (365 nm and 400 nm), through the visible spectrum, to three infrared bands (725, 850, and 930 nm). Just as in astronomy, imaging in different wavelengths reveals hidden features. Dr. Bill Christens-Barry of R.B. Toth then processed the resulting stack of black-and-white images to draw out faint or even invisible features and minimize aspects of the 700-year-old document that obscured the legibility of the Magna Carta.
This breakthrough allowed historians Dr. David Carpenter and Dr. Nicholas Vincent to read previously illegible sections of the document. Multispectral imaging not only revealed faded text but also preserved evidence of the document’s material condition, offering insight into its long and complex history. Through comparative and textual analysis with the five other known complete copies and one in fragments of the Magna Carta, the scholars concluded that Harvard's matched the other originals.
Carpenter and Vincent then undertook the painstaking task of tracing the document’s provenance, which was only known for the year before Harvard purchased it. By reaching out to descendants of the previous owner and scouring archives, they followed its trail back to a 1300 copy commissioned for the English district of Appleby. Combined with the imaging evidence, this detective work confirmed that Harvard's Magna Carta is indeed an original from 1300.
And it all began with a simple afternoon test of a new imaging system.
Why Does the Harvard Plate Stacks Need a Cutting-Edge Camera Found Nowhere Else?
For the past three years, the Harvard Plate Stacks at the Center for Astrophysics | Harvard & Smithsonian has partnered with imaging experts Mike Toth and Dr. Bill Christens-Barry of R.B. Toth Associates LLC to develop a state-of-the-art digitization system. Under the leadership of Curator Thom Burns, the goal has been to extend digitization beyond what the original DASCH (Digital Access to a Sky Century @ Harvard) project achieved.
DASCH successfully digitized 429,274 glass photographic plates of the night sky, using a custom robotic scanner designed for direct-image plates. However, roughly 250,000 other plates remain untouched. These include spectral field and single-spectrum plates used in groundbreaking work like the Henry Draper Memorial Catalogue and the Harvard Spectral Classification system. Also yet to be digitized are plates depicting solar system objects—images of the Sun, Moon, planets, comets, and meteors—as well as thousands of plates capturing Earth-based scenes: people, instruments, observatories, and more.
Digitization is an ongoing, iterative process. As technology improves, so too must our tools for preserving and understanding analog materials. The new system uses specialized lighting and a powerful Phase One camera to capture plates in narrow bands across the electromagnetic spectrum, from infrared to ultraviolet.
This matters because these plates are more than just astronomical data. Many are annotated (on the glass side) by generations of researchers, including the pioneering women known as the Harvard Computers. These notes provide vital historical and scientific context. On the emulsion side, microscopic silver salts preserve the light of stars and galaxies collected over more than a century, nearly three times the span of digital data collected by modern CCD telescopes.
With this advanced imaging system, the Plate Stacks can now digitize plates in a way that preserves both the data and the annotations, without erasing any part of the artifact. Unlike DASCH, which involved removing annotations before scanning, the new system is completely non-destructive and opens the door to simultaneous scientific and historical study. This new system will continue to be a resource for research across Harvard. The system is also being designed to be transportable to help other observatories or archives digitize their collection of astronomical glass plates.
The Harvard Plate Stacks will continue to push cutting-edge imaging. It is poised to reveal even more hidden stories, from the cosmos to the court.